Process for improving the tinctorial characteristics of polyolefin fibres



United States Patent 3,151,928 PROCESS FOR IMPROVING THE TINCTORIAL CHARACTERISTICS OF POLYOLEFIN FIBRES Vittorio Cappuccio and Ubaldo Riboni, Terni, Italy,

assignors to Montecatini, Societa Generale per IIndustria Mineraria e Chimica, Milan, Italy No Drawing. Filed Apr. 28, 1961, Ser. No. 106,169 Claims priority, application Italy May 5, 1960 3 Claims. (Cl. 8115.5)

The present invention relates to a process for improving the tinctorial characteristics of fibres obtained from mixtures containing olefin polymers, especially polypropyl ene, and basic nitrogen compounds, such as:

(A) The polyvinylpyridine, obtained using radicalic or stereospecific catalysts.

(B) The condensation products of epichlorohydrin, aliphatic amines and diamines; of epichlorohydrin, aliphatic amines and imines; of epichlorohydrin, aliphatic amines and diimines (piperazine); of alkylchlorides, diamines and epichlorohydrin.

(C) The condensation products of halogen derivatives with diamines and the like.

In preceding US. patent applications Serial No. 702,- 430, filed December 12, 1957 (now US. Patent No. 3,107,228), and Serial No. 30,732, filed May 23, 1960, there are described processes for obtaining textile fibres possessing some receptivity for dyes, especially acid dyes. These processes comprise the extruding of mixtures of crystalline isotactic polyolefins, more particularly polypropylene consisting prevailingly of isotactic macromolecules, and basic nitrogen compounds, such as the polyvinylpyridines, the condensation products of dihalogen-derivatives and diamines, the basic condensation products of epichlorohydrin, and the like.

Moreover, a process for improving the dye fastness, the hand and the other characteristics of fibres, made from mixtures of polyolefins and basic nitrogen compounds, by treating the fibres with mono and di-epoxy compounds is also described in the US. patent application Ser. No. 23,129, filed on April 19, 1960.

The present invention can be utilized advantageously in addition to said process for improving hand, at a sequence stage to be selected as desired.

It has now been surprisingly found, that when the fibres obtained from mixtures containing crystalline polyolefins, especially polypropylene consisting prevailingly of isotactic macromolecules, and basic nitrogen-containing compounds are subjected to a treatment with sulfuric acid, there is obtained a more rapid exhaustion of the dyeing baths, purer shades and better color fastness, especially to washing.

Fibres of polypropylene consisting essentially of isotactic macromolecules are especially suitable for use in the process of the present invention.

It is therefore an object of the present invention to provide a process for improving the tinctorial characteristics of fibres obtained by the extrusion of mixtures of crystalline isotactic polyolefins and basic nitrogen containing compounds.

This object is achieved by a treatment such as by contacting with sulfuric acid.

The treatment with sulfuric acid according to the present invention can be carried out with or without before or after the stretching of the fibres and at some sequence stage such as, before or after the treatment with monoor diepoxy compounds.

The treatment can be carried out continuously or batchwise, for times varying from 1 second to 60 minutes, at temperature of between 15 and 100 C.

Aqueous sulfuric acid solutions, having concentrations "Ice varying from 0.01% to 30% by weight, are employed.

After the treatment with sulfuric acid, any sulfuric acidtreatment-products, such as excess or residual sulfuric acid or such as reaction products, of the sulfuric acid, are removed, e.g., the fibres are washed with water and/ or alkaline substances (alkaline o-r earth-alkaline hydroxides, carbonates or the like).

The following examples are given to illustrate the present invention without limiting its scope.

As is known to the art subsequent to the discoveries of Natta et al., the heptane residue percent in the polypropylene of the following specific examples is an indication of the presence of isotactic macromolecules (as defined by Natta et al., for example, in US. Patent No. 2,882,263). The polypropylene of the following examples therefore consists essentially of isotactic macromolecules.

Example 1 A yarn is prepared from a mix consisting of 1,300 g. of a polyimine condensate, and of 36 kg. of polypropylene having the following characteristics; [1 ]=1.43 (measured in tetrahydronaphthalene at C.), ash content 0.028%, residue after heptane extraction 95.7%.

(The polyimine condensate was prepared by dissolving 1160 g. of hexamethylene diamine in 1800 cc. water at room temperature while agitating in a 6 litre glass vessel, by heating the solution to 90 C. and by adding to it 897 g. of dichloroethane and a 50% aqueous sodium hydroxide solution (725 g.). When the addition is completed, the reaction is continued at 90 C. for 3 hours, it is then cooled at 20-25 C., an upper solid layer is removed to which 2000 cc. water are added, the mass is heated to 7080 C. and decanted While the Water is removed by distillation. A solid polyimine condensate is obtained.)

The polypropylene-polyimine condensate mix is granulated by extrusion in a screw device at C.

The granulate is spun under the following conditions:

Spinneret type mm 60/0.8 16' Screw temperature C 240 Head temperature C 230 Spinneret temperature C 220 Maximum pressure kg./cm. 27 Winding speed m./minute 310 The filaments leaving the Spinneret are Wetted with an aqueous solution containing 10% ethylene glycol diglycidyl ether.

These filaments are then stretched under steam with a stretching ratio of 1:64 and then crimped. The crimped roving is passed into a vessel containing a 5% aqueous sulfuric acid solution maintained at 25 C.

The speed of the entering roving is regulated so as to allow the filaments a residence time in the sulfuric solution of 5 seconds. From the sulfuric solution the filaments pass into another vessel containing a 10% aqueous sodium bicarbonate solution.

They are then cut and dried. Staples thus obtained are dyed to intense colors with acid, metallizable, plastosoluble (disperse) and vat dyes.

The fastness of the colors obtained on the fibres subjected to the contact with sulfuric acid according to the present invention, especially the fastness to washing, is clearly better than that of the colors obtained on corresponding fibres, by otherwise identical dyeing processes not subjected to this contact with sulfuric acid.

Example 2 A yarn identical with that of Example 1 is prepared; however, the filaments leaving the spinnerett are not epoxidized.

The filaments, after being stretched under steam with a stretching ratio of 1:6.4, are wetted with a 5% aqueous ethyleneglycoldiglycidylether solution and then treated in autoclave with steam under vacuum (150 mm. Hg) at 105-11'0" C.

These filaments are then passed in a vessel containing a 10% aqueous sulfuric acid solution at 25 C. The speed of the entering roving is regulated so as to allow the filaments a residence time in the sulfuric solution of 2 seconds.

, From the sulfuric solution the fibres pass into a vessel containing a 10% aqueous sodium bicarbonate solution. They are then cut and dried. Staples thus obtained are dyed intensely with acid, metallizable, plastosoluble and vat dyes. The fastness of the colors obtained on the fibres subjected to the contact with sulfuric acid according to the invention, especially the fastness to washing, is better than that of the colors obtained on correspondingly dyed fibres not subjected to this contact with the sulfuric acid.

Example 3 A yarn is prepared by mixing 900 g. of polyvinylpyridine, prepared by polymerizing 2-vinylpyridine with .the aid of stereospecific catalysts (of the Grignard type), with 9.100 kg. of polypropylene having the following characteristics: intrisic viscosity measured in tetrahydronaphthalene at 135 C.:1.37, ash cntent=0.024%, residue after heptane extraction=96.3

The mix is granulated at 200-210 C. and the granulate is spun under the following conditions:

Spinneret type mm 60/0.8 16 Screw temperature C 230 Head temperature C 220 Spinneret temperature C 220 Maximum pressure kg./om. 50 Winding speed m./min 250 The filaments leaving the spinneret, after being stretched under steam with a stretching ratio of 1:5, are wetted with a 10% aqueous ethylene glycol diglycidyl ether solution, treated with steam in an autoclave under Vacuum (160 mm. Hg) at 105110 C. and then crimped and cut.

The staple thus obtained is contacted for 10 minutes at the boiling point with a 5% aqueous sulfuric acid solution with a fibre/ bath ratio of 1 :20.

The fibres obtained quickly exhaust the bath and the colors obtained have a fastness, particularly to washing, clearly better than that of the colors obtained on correspondingly dyed fibres not subjected to a treatment with sulfuric acid.

Many variations and modifications can of course be 4 made without departing from the spirit of the above invention.

Having thus described the invention, what it is desired to secure and claim by Letters Patent is:

1. In a process for improving the tinctorial characteristics of fibers prepared by (l) extruding a mixture containing (a) a polypropylene consisting essentially of isotactic macromolecules, (b) a basic nitrogen containing compound selected from the group consisting of polymeric vinyl pyridines and condensation products of dichloroethane with diarnines, (2) stretching the extruded fibers, (3) subjecting the stretched fibers to a treatment with a compound selected from the group consisting of mono-epoxy compounds and di-epoxy compounds, the improvement which comprises contacting the resulting fibers with an aqueous sulfuric acid solution having a concentration of from 0.01 to: 30% by Weight, at a temperature of from 15 to C. and removing acid prior to dyeing said fibers.

2. A process according to claim 1, wherein said treatment with sulfuric acid is carried out in a continuous manner.

3. A process according to claim 1, wherein said treat- References Cited in the file of this patent UNITED STATES PATENTS 1,285,738 Klauser Nov. 26, 1918 1,998,576 Heberlein Apr. 23, 1935 2,536,893 Speakman et al. Jan. 2, 1951 2,668.134 Horton Feb. 2, 1954 2,882,263 Natta et a1. Apr. 14, 1959 2,903,381 Schroeder Sept. 8, 1959 2,937,066 Walles May 17, 1960 3,013,998 Battaglioli Dec. 19, 1961 3,107,228 Cappuccio et al. Oct. 15, 1963 FOREIGN PATENTS 613,817 Great Britain Dec. 3, 1948 1,006,828 Germany Apr. 25, 19:57

584,249 Italy Oct. 24, 1958 617,236 Italy Feb. 16, 1961 OTHER REFERENCES Encyclopedia of Science and Technology, 1960, vol. 2, page 252, vol. 13, published by McGraW-Hill, New York, NY. Copy of record.

Handbook of Chemistry and Physics, 34th edition,, pages 1790 and 1787, 1952/53, Chemical Rubber Co., Cleveland, Ohio. Copy of record.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3, 151,928 Oetober 6, 1964 Vittorio Cappuccio et a1 It is hereby certified, that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected belo Column 1, line 16, for "polyvinylpyridine" read polyvinylpyridines column 4, line 20, before "acid" insert said Signed and sealed this 26th day of January 1965.

(SEAL) Attest:

ERNEST W. SWIDER' EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. IN A PROCESS FOR IMPROVING THE TINCTORICAL CHARACTERISTICS OF FIBERS PREPARED BY (1) EXTRUDING A MIXTURE CONTAINING (A) A POLYPROPYLENE CONSISTING ESSENTIALLY OF ISOTACTIC MACROMOLECULES, (B) A BASIC NITROGEN CONTAINING COMPOUND SELECTED FROM THE GROUP CONSISTING OF POLYMERIC VINYL PYRIDINES AND CONDENSATION PRODUCTS OF DICHLOROETHANE WITH DIAMINES, (2) STRETCHING THE EXTRUDED FIBERS, (3) SUBJECTING THE STRETCHED FIBERS TO A TREATMENT WITH A COMPOUND SELECTED FROM THE GROUP CONSISTING OF MONO-EPOXY COMPOUNDS AND DI-EPOXY COMPOUNDS, THE IMPROVEMENT WHICH COMPRISES CONTACTING THE RESULTING IMPROVEMENT WHICH COMPRISES CONTACTING THE RESULTING FIBERS WITH AN AQUEOUS SULFURIC ACID SOLUTION HAVING A CONCENTRATION OF FROM 0.01 TO 30% BY WEIGHT, AT A TEMPERATURE OF FROM 15* TO 100*C. AND REMOVING ACID PRIOR TO DYEING SAID FIBERS. 